Sunday, June 28, 2009

Benign Decline?

For many decades now intellectuals, policy makers, humanitarian organizations and environmentalists have put time, money and effort into worrying about the negative impacts of humanity's ever-increasing population. It is certainly a problem worth worrying about. Everything from food and water shortages to increased disease transmissibility to habitat destruction and global climate change are made worse by overpopulation. Jared Diamond, in his excruciatingly detailed and example rich tome, Collapse, explores how human societies can fail when their population outgrows the resource base on which they depend. World population projections estimate that we will top out at 9 to 12 billion some time between 2050 and 2075. That is a lot of people for this little planet, and the risks are real and enormous. But I've been thinking about the opposite problem, one we have thought very little about, but is predicted in the same forecasts, declining population.

World population is predicted not to level off and stay at 9 to 12 billion, but to begin declining. There are two main reasons for this. First, the fertility declines that have driven the demographic transitions in rich countries are predicted to eventually reach poorer and then poorest countries as well. There is good evidence that this is already happening, as education of females and availability of information have reached places like Iran and India, fertility rates in those places has dropped very dramatically and without Chinese style coercion. Fertility rates are declining almost everywhere, even if they are still quite high in some places. The countries that undergo this transition latest are expected to still get there eventually. If the whole world had fertility rates like what the Japenese have, world population would eventually decline.

The second reason population is expected to decline dramatically is what is called population momentum. A population that had a lot of babies 20-30 years ago inevitably has a lot of babies now, because of the large number of young women reaching their peak reproductive capacity. Iran is a perfect example of this. Iran is still producing an enormous number of babies, even though per-woman fertility has declined dramatically, because there are just so many reproductive age women who were born when fertility was extremely high 20-30 years ago. Americans are familiar with this effect from the "echo boomers" the large cohort of children born in the 60s and 70s as offspring of the baby boomers. Much of what is currently carrying world population upward is this type of momentum. Much of the world still has a very young (median age in Pakistan is about 16), and therefore reproductive, population. As fertility rates decline and longevity decreases, world population is aging dramatically. Median age in Japan is about 47 and rising fast. By 2050, the UN predicts that median age in Pakistan will be closer to 35 and Japan closer to 55.

Somewhere around there world population will begin to decline, slowly at first, and then more rapidly. That is the prediction anyway. The problem is that all of our models are predicated and tested based on increasing world population. World population has increased every year since before the advent of modern science. And it is not only our demography that is based on the assumption of ever increasing population. Our entire economic system is built around the idea of ever-expanding demand driven by ever expanding population. We know how to add new housing developments, houses, cities, businesses, banks and so forth. We know how to tear down small buildings to make space for bigger, taller ones. We have no system for dealing with declining population. How should a business respond if its potential audience gets smaller every year? How should a city respond if fewer and fewer of its housing units are occupied? How should a family respond if there is no one to take over the family business or farm? How should a government respond if there are too few people to pay its taxes or fill its military?

We do have case studies of this sort of thing. Flint, Michigan is talking about condemning and leveling not just individual homes, not just whole neighborhoods, but major portions of the city that are no longer viable because the population of that city has shrunk so fast. Japan, Germany and much of the former Soviet Block are experience population decline, and adapting to it with various degrees of success. The countries that do well despite population decline seem to be those that base their economies on exports to other regions where population is still increasing. If domestic demand declines but overall demand continues to rise, it may not be such a problem. But what will happen if population is declining almost everywhere? Will people or nations increase fertility in response? Will the general lack of children induce even more people to not have children, driving fertility even further down? Will we develop economic and development structures that thrive on population decline, as our current system requires population growth?

Michigan's population decline is directly attributable to collapse in demand for Michigan's main product. Population declines in Eastern Europe are similarly caused by politial, economic and social decline. The types of population declines Jared Diamond wrote about were caused by collapses of ecologies and socieites. If we manage to get through the population maximum of the 21st century without major collapses, we may be faced with the relatively novel situation of benign decline. That can only happen if we build systems that can function and thrive with declining populations. We don't yet know how to do that.

Monday, June 22, 2009

Behavio(u)r defined.

Published in this month's Animal Behaviour. British spelling.

Behavioural biologists do not agree on what constitutes behaviour

Daniel A. Levitis, William Z. Lidicker Jr. and Glenn Freund

"Behavioural biology is a major discipline within biology, centred on the key concept of ‘behaviour’. But how is ‘behaviour’ defined, and how should it be defined? We outline what characteristics we believe a scientific definition should have, and why we think it is important that a definition have these traits. We then examine the range of available published definitions for behaviour. Finding no consensus, we present survey responses from 174 members of three behaviour-focused scientific societies as to their understanding of the term. Here again, we find surprisingly widespread disagreement as to what qualifies as behaviour. Respondents contradict themselves, each other and published definitions, indicating that they are using individually variable intuitive, rather than codified, meanings of ‘behaviour’. We offer a new definition, based largely on survey responses:

Behaviour is the internally coordinated responses (actions or inactions) of whole living organisms (individuals or groups) to internal and/or external stimuli, excluding responses more easily understood as developmental changes.

Finally, we discuss the usage, meanings and limitations of this definition."

Tuesday, June 09, 2009

Demography of Islamic Extremism

The size of any population is determined by births, deaths, immigrations and emigrations.

Change in population= Births-Deaths+Immigrations-Emigrations.

This is one of the first facts mentioned in any class or text on demography, and is so obvious that we often simply take it for granted. But like many concepts which are obvious in context, this can be easily forgotten.

I am thinking here particularly of the population President Obama refers to as "Islamic Extremists." What determines the global population of these extremists? We can assume that no one is born as a violent extremist, so it isn't births. The Bush administration tended to assume the population of extremists was a declining stock, whose numbers would be determined primarily through deaths. We saw how well that worked out. What the Obama folks seem to understand, and what I believe to be the goal of much of the US's redirected foreign policy and rhetoric, is that the number of violent extremists in the world is determined primarily through immigration (recruitment) and emigration (defections, retirements, going homes, laying down of arms).

Let's assume, again that no one is born a violent extremist. Let's further assume that 1% of the world's 1.5 Billion Muslims have the backgrounds and personality traits such that the proper circumstances could push them to violent extremism. We estimate 15 Million potential extremists. What proportion of those will turn to violent extremism at any one time? The answer is clearly a very small. Depending on how we define our terms, maybe there are 150,000 violent Islamic extremists in the world today. That is if we add together the Taliban forces, al Qaeda, al Shabab, Hamas fighters, Hezbolah fighters and so forth. It is a rough estimate, but will do for now. We estimate that 1% of 1% of the worlds' Muslims are violent extremists.

What if, instead of 1% of potential extremists becoming actual extremists, 2% were? Then we double the number of extremists, to 300,000. If only 0.5% of those with the potential for extremism experienced circumstances causing them to act on that potential? Then we have 75,000 extremists, and our problem of eliminating extremists is half solved.

Nothing the US does is going to kill 75 thousand extremists, or 150 thousand extremists. Not that the US military isn't still trying to kill as many violent extremists as possible, but we seem to kill maybe five thousand a year, if we are lucky. Let's look again at our equation and start plugging numbers into it.

Change in population= Births-Deaths+Immigrations-Emigrations.
Change in population= 0-5000+Immigrations-Emigrations.

Let's plug in numbers for the two scenarios we outlined above.

Change in population= 0-5000+150,000=145,000
Change in population= 0-5000-75,000= -80,000

The number of extremists killed is largely irrelevant in these two scenarios. If we kill 15,000 instead of 5,000, we end up with
Change in population= 135,000 or -90,000

The potential fluxes through immigration and emigration are just so much bigger than the number we kill. Nor are these numbers necessarily independent. One can easily imagine that if brother A has the capacity to be a violent extremist, brother B is more likely than average to have the same capacity. Killing A may increase deaths by one, but it may also increase immigrations by one. If there is a brother C, it may increase immigrations by two.

The point of all this is to say that the most effective way to manage the population of violent extremists is decrease their recruiting and increase the number of their colleagues who go home. Killing them is useful in limiting the damage they can do, reducing their moral and providing alternative opportunities to those who could join them. But the number killed is far less important than the effect that that killing has on recruiting and defections.

I could get into a long discussion of what I think will ultimately influence that (Immigration-Emigration) term, but I won't, as that would stray too far from anything I have any scientific basis for considering. Rather I will simply say that I think the US government has finally caught on that the conditions determining (Immigration-Emigration) are far more important than the number killed, and I think this is a key insight.

Wednesday, June 03, 2009

Scientific publishing after paper

Yesterday I submitted a paper to the Proceedings of the National Academy of Sciences. Like most high profile journals they have strict page limits, and my paper was carefully planned to be just under the limit. I got an email from them today saying that they had recently changed the format in which references are given in the journal, and I would have to use the new, longer, format, and resubmit. I had 65 references, so the longer format made my paper half a page too long, which means I have spent the morning making the paper shorter again.

All this has got me thinking about the future of publishing, as fewer and fewer people read their journals on actual paper. The traditional justification for page limits, and a lot of the other rules journals have, was that it cost the journal money to print the extra pages, or the color, or figures above a certain size. Several journals, including PNAS, have even offered authors the option of going over the page limit or adding colors, but paying the extra printing costs. What happens to these limitation as fewer and fewer subscribers bother with the paper edition, and almost everyone goes straight to the digital version?

We are not near abandoning the paper journal yet. Even journals that start out as internet only, as PLoS did a few years back, often end up printing a paper edition because libraries and some readers (especially the older and more established) really like have a paper journal to thumb through. But this is changing. I, and most researchers my age, read almost everything from a digital copy. Some people print out the individual articles they want to read, others read from a screen. It is rare to see anyone my age or younger reading from a bound print journal, unless of course it is one of those rare journals that isn't available online. It is becoming increasingly common for libraries, to save shelf space and money, to provide access to only the digital copies of the less frequently read journals. There are journals which can only be found online, and I suspect their number will increase rapidly over the next decades. These journals (e.g. JoVE) can be far more multimedia than the old ink on rectangle.

So far, this seems to be having relatively little effect on the page limit. Journal editors want authors to get to the point, even if they don't have to worry about the cost of paper and ink. Journals are increasingly offering the option of accompanying the paper with supplemental online material. Those experimental protocols, that video sequence, the large table and the mathematical appendix can all be posted online, with the permalink listed in the main paper and hyperlinked directly from the digital versions. PNAS allows up to ten such files, and the length of all these add-ons often surpass the article itself, but without busting the page limit.

Annoying as it is to have to go through and find three more lines of text to cut to get down to that page limit, I suppose I should be happy that the page limit will be around long after the page itself has gone the way of the mimeograph. I don't want to have to read as much as all those people would write.

I do think the journals themselves will last, even if only online. Someone has to organize the peer review, and everyone needs to have a limit on the number of places they need to look to find relevant papers. I doubt I will see the day when one can be a successful scientist just by uploading my own work onto my own website and inviting people to read it.

Monday, June 01, 2009

A lack of enemies

I am working on submitting a paper to the Proceedings of the National Academy of Sciences. They ask that I suggest editors and reviewers who are qualified to evaluate my paper. They also give me the option of listing a few people who I want to not be given the chance to peer review my paper. I assume this is so that if two authors have written on the same topic, and clashed on that topic, one can't keep the other from publishing by writing very negative reviews. It is a way to ask that your paper not be sent to your rival and then treated unfairly.

There are people whose previous conclusions I disagree with, but nobody I can think of who I have any reason to believe would treat my paper unfairly. I haven't been in the field long enough or published enough papers to make enemies yet. Something to look forward to, I guess.